1. Field of the Invention
The present invention relates to a microwave oven, and more particularly to an operation control method of a microwave oven constructed such that a cooking end preparation sound is generated before cooking end and cooking end sound is generated when cooking is finished to notify a user a cooking process and to allow the user to know the cooking completion in advance.
2. Description of the Prior Art
Generally, a microwave oven is constructed such that high voltage is generated from a high voltage transformer by a predetermined power source supplied from outside and microwaves are generated by a magnetron according to the high voltage to thereby heat and cook foodstuff in a cooking chamber.
In the microwave oven thus constructed, when a user inserts a foodstuff into a cooking chamber (not shown), sets up a cooking course (by way of example, cooking function, cooking time, etc.) through a key input unit (not shown) and inputs a cooking start, the key input unit outputs to a controller (not shown) an electrical key signal corresponding thereto.
Next, when the controller outputs a control signal to a magnetron driving unit (not shown) to drive a magnetron (not shown) according to the key signal, and when the magnetron driving unit drives the magnetron according to the control signal, microwaves are generated to heat and cook foodstuff in a cooking chamber.
When the controller drives the magnetron and counts a cooking time and when the counted time is a cooking completion time (to be more specific, when the cooking time established by a user is a cooking completion time), the controller outputs to the magnetron driving unit a control signal to stop the magnetron and simultaneously outputs a control signal to a buzzer (not shown) to generate a cooking completion sound.
Next, when the magnetron driving unit stops the magnetron according to the control signal, the magnetron is stopped, and, by which, microwaves are not generated to thereby stop cooking the foodstuff in the cooking chamber and the buzzer generates a completion sound according to the control signal to notify the user of the cooking completion and completes the overall cooking processes.
However, there is a problem in the conventional microwave oven thus constructed in that a cooking process sound is not generated during the cooking, and a cooking completion sound is generated after the cooking to notify the user only upon the cooking completion, so that the user cannot know the state of the cooking process nor is he given a time allowance for preparing the cooking completion (by way of example, when the user cooks, a preparation time for performing a next cooking process with the foodstuff cooked by the microwave oven is not given), thereby providing an inconvenience to the user.